Surface Plasmon Resonance Spectroscopy: A Versatile Technique in a Biochemist’s Toolbox

Abstract

Surface plasmon resonance (SPR) spectroscopy is a powerful, label-free technique to monitor noncovalent molecular interactions in real time and in a noninvasive fashion. As a label-free assay, SPR does not require tags, dyes, or specialized reagents (e.g., enzymes–substrate complexes) to elicit a visible or a fluorescence signal. During the last two decades, SPR has been broadly applied to study of noncovalent interactions of protein–DNA, protein–cell, RNA–DNA, DNA–DNA, protein–protein, protein–carbohydrate, small molecule–macromolecule (e.g., receptor–inhibitor complex), protein–peptide, and self-assembled monolayers. In addition, SPR has been successfully applied to drug discovery ligand-fishing and clinical immunogenicity studies (i.e., to monitor an immune response against a therapeutic agent). SPR spectroscopy can address questions such as specificity of an interaction, kinetics, affinity, and concentrations of selected molecules present in a sample of interest. Given the current enhancements in hardware and software capabilities along with its ease of use and maintenance, SPR experiments can be designed for upper-level undergraduate biochemistry, biophysics, and physical chemistry laboratory courses. In this article, an overview of SPR phenomenon, instrumentation, sensor immobilization, and its selected applications is presented.